Studies on the Properties of the Oxy-Acetylene Flame (Report 4)

Hydrogen and Nitrogen in the Depasited Metal Mede under Various Conditions of the Oxy-Acetylene Flame

Abstract

It is believed that the contents of hydrogen and nitrogen in the deposited metal made by the oxyacetylene flame are so small that the effect of these gases are very slight. This fact has been ascertained by authors by measuring the contents of these gases.
1. Hydrogen : The analysis of the deposited metal for dissolved hydrogen was made by the Glycerine Method. As is shown in Fig. 3, the results of these analyses indicate that the amount of extracted gas from the deposited metal decreases as the mixed ratio (O₂/C₂H₂) of the flame increases. This amounts, when compared with those obtained from arc welding (except the low-hydrogen type electrode), are much smaller. Table 1 gives the results of the hydrogen analysis (Vacuum Heating Extraction Method) of the metal deposited in the neutral flame. The hydrogen content decreases as the welding time increases.
2. Nitrogen : The nitrogen content of the deposited metal melted under various conditions of the oxyacetylene flame using different filler rods is illustrated in Fig. 9. The nitrogen content increases as the mixed ratio of the flame increases. These nitrogen contents are nearly equal to or a little more than that of arc welded metal obtained from heavy coated electrode by melting it by arc. In the welding operation, the flame may introduce nitrogen from the air into the deposited metal. This tendency is recognized remarkably clear when the mixed ratio is increased and also when the filler metal with a smaller diameter is used.